1. Field of the Invention
This invention relates to a device for processing photographic plates wherein the process to which the plates are subjected may include exposure to developing fluid in addition to a wash-off facility incorporating a scrubbing action to remove preselected portions of the exposed material placed on predetermined surfaces of the photographic plates.
2. Description of the Prior Art
In the graphic arts industry, the existence and value of machines and methods for developing and processing of wash-off reproduction materials is well recognized. There are numerous types of wash-off systems, the majority of which are designed for use in combination with bichromate and diazo emulsion coating. Wash-off processing, however, is not limited to these restricted chemical families. During processing, a number of photographic emulsions harden on exposure and development. Others are caused to adhere to the base sheet more positively. One group of silver emulsions, (colloid tanning agents, and a reduceable silver salt which, on exposure to light, yields a tanned insoluble negative image) can be coated on materials including cloth, paper and stable base films. The non-image areas are soluble in water or developer and are washed away during processing. Other techniques coat substrates with diazo compounds which, when exposed and developed, harden and adhere to the base material. Unexposed areas are easily removed with developer or water. Both auto-positive and negative working materials are available for such application. Similarly a full range of colored material is available in addition to the commonly used black.
The materials mentioned above, as well as others commonly known in the graphic arts industry can presently be processed by hand rubbing exposed materials with activator and water washing, (manual rub) or spraying. After wash-off it is common to use any conventional film dryer for drying the copy or the copy can simply be hung on a line for atmospheric drying.
In approximately the last ten years there has been increased activity on the part of those involved in the graphic arts industry for development of additional wash-off material. Emulsion technology has provided a faster development and higher densities, not to mention improved image adhesion coupled with ease in wet removal of image. The major manufacturers and development in this industry are and have been at work in several areas of the wash-off processing.
While wash-off processing has become increasingly active in the graphic arts industry, hardware utilized for this processing is still relatively high priced because of the unnecessary sophistication of structure design used in these processors. Hardware wash-off processors presently commercially available and generally in the range from $12,000 to $25,000. It has been found, however, that even with this relatively sophisticated and overly complex equipment, performance in a number of the presently commercially available machines, in terms of quality of product being processed is less than satisfactory. In wash-off processing, removal of certain waste particles from the exposed surface of the plate must be accomplished without scratching or otherwise causing abrasion between the removal element and the developed portion of the surface of the plate.
Accordingly, there is a great need in the graphic arts industry for a simple, easily operated relatively low cost machine that provides a dry-to-dry wash-off processing facility at relatively fast processing speeds. Such machine should be capable of eliminating scratching and other damage to sheets or plates that are processed.